Redefining Plain Pagestyle removes header line from other pages

Question

I am typesetting a document with Latex, in which I want the page numbers at right bottom. The following MWE works fine, except that the chapter title pages have number in the center.

\documentclass[12 pt, oneside]{extbook} %extarticle provides additional font-sizes

%formatting header and footer

\usepackage{fancyhdr}

\pagestyle{fancy}

\fancyhead{}

\fancyfoot{}

\fancyhead[CE, CO]{\scriptsize Qualitative Analysis of Sanskrit E-learning Systems}

\fancyfoot[RO, LE]{\thepage}

\usepackage[english]{babel}

\usepackage{blindtext}

\pagestyle{fancy}

\begin{document}

\frontmatter

\pagestyle{plain}

\blindtext[10]

\pagestyle{fancy}

\fancyhead[CE, CO]{\scriptsize Table of Contents}

\tableofcontents

\mainmatter

\pagestyle{fancy}

\fancyhead[CE, CO]{\scriptsize Chapter1}

\chapter{chapter1}

\blindtext[20]

\fancyhead[CE, CO]{\scriptsize Chapter2}

\chapter{chapter2}

\blindtext[20]

\end{document}

On searching to resolve this problem, I found this bit of code to redefine the plain pagestyle.

%Redefining plain style for chapter title pages

\fancypagestyle{plain}{

\fancyhf{}
     \fancyfoot[R]{\thepage}
    \renewcommand{\headrulewidth}{0pt}
}

But if I add this code, it removes header line (headrule) from all pages.

Here is the complete MWE

\documentclass[12 pt, oneside]{extbook} %extarticle provides additional font-sizes

%formatting header and footer

\usepackage{fancyhdr}

\pagestyle{fancy}

\fancyhead{}

\fancyfoot{}

\fancyhead[CE, CO]{\scriptsize Qualitative Analysis of Sanskrit E-learning Systems}

\fancyfoot[RO, LE]{\thepage}

%Redefining plain style for chapter title pages

\fancypagestyle{plain}{

\fancyhf{}
     \fancyfoot[R]{\thepage}
    \renewcommand{\headrulewidth}{0pt}
}

\usepackage[english]{babel}

\usepackage{blindtext}

\pagestyle{fancy}

\begin{document}

\frontmatter

\pagestyle{plain}

\blindtext[10]

\pagestyle{fancy}

\fancyhead[CE, CO]{\scriptsize Table of Contents}

\tableofcontents

\mainmatter

\pagestyle{fancy}

\fancyhead[CE, CO]{\scriptsize Chapter1}

\chapter{chapter1}

\blindtext[20]

\fancyhead[CE, CO]{\scriptsize Chapter2}

\chapter{chapter2}

\blindtext[20]

\end{document}

What do I do to retain headrule on pages other than the plain pages? (To clarify, I want plain pages with no header, but page numbers on the right bottom, fancy pages with header text, headrule, and page numbers on right bottom).

Answer 1

It's better to define two page styles; the one redefines plain while the other defines what should happen outside of the plain pages.

\documentclass[twoside]{extbook} %extarticle provides additional font-sizes

%formatting header and footer
\usepackage{fancyhdr}

\fancypagestyle{newpagestyle}{%
  \fancyhf{}% Clear header/footer
  \fancyhead[CE, CO]{\scriptsize Qualitative Analysis of Sanskrit E-learning Systems}
  \fancyfoot[RO, LE]{\thepage}
  \renewcommand{\headrulewidth}{.4pt}
}

\pagestyle{newpagestyle}% Set the default page style

%Redefining plain style for chapter title pages

\fancypagestyle{plain}{
  \fancyhf{}% Clear header/footer
  \fancyfoot[R]{\thepage}
  \renewcommand{\headrulewidth}{0pt}% Remove header rule
}

\usepackage[english]{babel}

\usepackage{blindtext}

\begin{document}

\frontmatter

\blindtext[10]

\tableofcontents

\mainmatter

\chapter{chapter1}

\blindtext[20]

\chapter{chapter2}

\blindtext[20]

\end{document}

Also, avoid setting the header before a call to \chapter, as in

\fancyhead[..]{...}
\chapter[..]{...}

Why? Because \chapter issues a \newpage which ships out the current page on which you've set header content.